Planetary transmission apparatus including vehicle-wheel hub

ABSTRACT

A planetary transmission for a vehicle, comprising a planet carrier, on which at least one planet wheel is mounted, a hub arranged for a vehicle wheel and connected to the planet carrier, and a static housing which is connected to the vehicle and in which the hub is mounted. A friction brake is arranged at an outer periphery of the planet carrier and is intended to brake the rotation of the planet carrier in relation to the static housing. The hub and the planet carrier are interconnected by a splined connection. According to an embodiment, an outer gear ring is arranged so as to interact with the at least one planet wheel, which outer gear ring is connected to the static housing by a second splined connection.

FIELD OF THE INVENTION

The present invention relates to a planetary transmission for a vehicle,comprising a planet carrier, on which at least one planet wheel ismounted, a hub arranged for a vehicle wheel and connected to the planetcarrier, a static housing which is connected to the vehicle and in whichthe hub is mounted, and a friction brake arranged at an outer peripheryof the planet carrier and intended to brake the rotation of the planetcarrier in relation to the static housing.

BACKGROUND OF THE INVENTION

It is previously known to arrange a planetary transmission inconjunction with the wheel of a vehicle. The drive shaft of the vehicleis then provided with an inner sun wheel for the planetary transmission,and a static housing surrounding the planetary transmission is providedwith an outer gear ring. The sun wheel and the gear ring interact withplanet wheels which are arranged on a planet carrier. The planet carrieris connected to a hub which is mounted in the static housing, and avehicle wheel can be mounted on the hub by means of wheel bolts. Byarranging a planetary transmission in conjunction with the wheel of avehicle, an increase in torque from the drive shaft to the wheel isobtained. In order to brake the vehicle, friction discs are arranged onthe periphery of the planet carrier, which interact with disc plateswhich are arranged in the static housing.

The construction of the known planetary transmission is such that it isnot suitable for large and heavy vehicles, such as industrial machinery,which would require, for example, a stronger hub bearing arrangement andthus a longer hub in the axial direction. This would, however, placegreater demands on the connection between the planet carrier and thehub, at the same time as it is desirable to keep the planetarytransmission as a whole as compact as possible.

SUMMARY OF THE INVENTION

The object of the present invention is to produce a planetarytransmission of the type indicated in the introduction, which eliminatesthe problems indicated above and aims to obtain as compact aconstruction as possible.

A further object of the invention is to produce a planetary transmissionwhich comprises relatively few components and is easy and inexpensive tomanufacture.

According to the invention, this is achieved by virtue of the fact thatthe hub and the planet carrier are interconnected by means of a firstsplined connection.

According to the invention, this is also achieved by virtue of the factthat an outer gear ring is arranged so as to interact with the at leastone planet wheel and that the outer gear ring is connected to the statichousing by means of a second splined connection.

Such a planetary transmission is compact and comprises fewer componentsthan the known planetary transmission in spite of the fact that theplanetary transmission is dimensioned so as to absorb considerablygreater forces than the known construction.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail below with referenceto the appended drawing which shows two exemplary embodiments and inwhich:

FIG. 1 shows a sectional side view of a planetary transmission accordingto a first exemplary embodiment of the present invention, and

FIG. 2 shows a sectional side view of a planetary transmission accordingto a second exemplary embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1, reference number 1 designates a planetary transmission for avehicle, which planetary transmission 1 comprises a planet carrier 2, onwhich a number of planet wheels 4 are arranged. From the engine orgearbox (not shown) of the vehicle, a drive shaft 6 extends, the outerend 8 of which comprises an inner sun wheel 10 for the planetarytransmission 1, which inner sun wheel 10 is intended to interact withthe planet wheels 4 on the planet carrier 2. The number of planet wheels4 according to the first exemplary embodiment in FIG. 1 is three, but itis also possible for the number of planet wheels 4 to be two, four ormore.

The term vehicle is intended to mean both vehicles which are intended tobe driven on the road and vehicles which are intended to be drivenoff-road, for example in the forest. Such vehicles may be dumpers,wheeled loaders, excavators or other industrial machinery.

The planet carrier 2 comprises a through-hole 12 which is provided withsplines 14. The centre line 15 of the hole 12 coincides with the axis ofrotation of the planet carrier 2. A tub 16, which at a first end 18comprises a journal 20 with splines 21, is arranged in the hole 12 ofthe planet carrier 2 and is thus radially connected to the planetcarrier 2. A plate 19 is connected to the hub 16 by means of screws 23and ensures that the hub 16 is axially connected to the planet carrier2. The hub 16 comprises at a second end 22 a fastening arrangement 24for a wheel 25 for the vehicle.

The hub 16 is mounted by means of roller bearings 26 mi a static housing28 which is connected to the vehicle. The hub 16 therefore rotates inrelation to the housing 28. Arranged in the housing 28 is an outer gearring 30 for the planetary transmission 1, which ring is intended tointeract with the planet wheels 4 on the planet carrier 2. The gear ring30 is connected to a first pressure plate 32 for a friction brake 34which will be described below.

The friction brake 34 comprises a set of friction discs 36 which arearranged on the periphery of the planet carrier 2. According to thefirst exemplary embodiment shown, the number of friction discs 36 iseight, but an arbitrary number of friction discs 36 is possible. Thefriction discs 36 are axially displaceable on splines 38 which arearranged on the periphery of the planet carrier 2. The friction discs 36are locked on the planet carrier 2 in the circumferential direction.

A set of disc plates 40 is arranged on splines 42 in the housing 28. Thedisc plates 40 are axially displaceable but locked in thecircumferential direction relative to the housing 28. The number of discplates 40 is preferably the same as the number of friction discs 36.Alternatively, the disc plates 40 may be arranged on the periphery ofthe planet career 2 and the friction discs 36 may be arranged in thehousing 28. The disc plates may be made of for example metal, plastic orcarbon fibre. It is also possible to use other materials.

A second pressure plate 44 is arranged so as to compress the frictiondiscs 36 and the disc plates 40 against the first pressure plate 32 whenthe rotation of the planet carrier 2 and thus the movement of thevehicle are to be braked. The second pressure plate 44 can be displacedaxially by a number of hydraulic pistons 46 which are distributed alongthe second pressure plate 44. The hydraulic pistons 46 displace thesecond pressure plate 44 axially by means of hydraulic fluid underpressure acting on the hydraulic pistons 46. The hydraulic fluid iscontained in an annular duct 48 arranged in the housing 28. Thehydraulic fluid is supplied to the annular duct 48 through a mouthpiece50 and a bore 51 in the housing 28. One or more helical springs 49,which are arranged between the first and second pressure plates 32 and44 respectively, return the hydraulic piston 46 to an initial positionafter braking.

The first and second pressure plates 32 and 44 respectively and also thefiction discs 36 and the disc plates 40 are preferably annular but theymay also be arranged in segments in a circular shape around the centreline 15 of the planet carrier 2.

According the first exemplary embodiment in FIG. 1, the hydraulicpistons 46 may alternatively be provided with a self-adjustment member52 which adjusts the initial position of the hydraulic piston 46 as thefiction discs 36 wear. The self-adjustment member 52 comprises a sleeve53 which is arranged with a grip fit in a blind hole 54 in the housing28. A pin 56, which extends through the sleeve 53, is at a first end 58connected to the hydraulic piston 46 and is at a second end 60 providedwith a head 62 which has a bearing surface 64 intended to bear againstan end surface 66 of the sleeve 53. As the friction discs 36 wear, thehydraulic piston 46 must travel a greater distance in order to compressthe friction discs 36 and the disc plates 40 against the first pressureplate 32 and thus a greater volume of hydraulic fluid is required. Inorder to overcome this problem, the grip between the sleeve 53 and theblind hole 54 is adapted in such a manner that the force from thehydraulic fluid that acts on the hydraulic piston 46 causes the sleeve53, with the aid of the head 62 of the pin 56, to be displaced in theblind hole 54 and to occupy a new position. The grip between the sleeve53 and the blend hole 54 is, however, adapted in such a manner that theforce from the helical spring 49 does not cause the sleeve 53 to bedisplaced in the blind hole 54, which means that the hydraulic piston 46will occupy a new initial position after the return stroke.

As an alternative, a sensor 68 may also be arranged in the housing 18,which senses the speed of rotation of the planet carrier 2 and thus alsothe speed of the vehicle. The sensor 68 is suitably arranged in a hole70 in the housing 28 at the first pressure plate 32 and is directedtowards the splines 38 on the periphery of the planet carrier 2, onwhich splines the first friction discs 36 are arranged The sensor 68then senses how fast the bars of the splines 38 pass the sensor 68,which is proportional to the speed of rotation of the planet carrier 2.In order to increase the accuracy of the sensing of the sensor 68, theplanet carrier 2 may alternatively be provided with teeth or splineswith a finer pitch next to the splines 38 on which the first frictiondiscs 36 are arranged.

In FIG. 2, a second exemplary embodiment according to the invention isshown. The planetary transmission according to this second exemplaryembodiment comprises an outer gear ring 30′ which is arranged so as toengage with the splines 42 which are formed in the housing 28. Theheight of the splines 42 has, in a portion that interacts with the gearring 30′, been reduced so as to form a stop or a beating surface for thegear ring 30′. The outer gear ring 30′ is on an outer periphery,provided with splines 74 which engage with the splines 42 in the housing28 to form a second splined connection.

The gear ring 30′ forms a first pressure plate 32′ for the frictiondiscs 36 and the disc plates 40 which form the friction brake 34. Thefriction brake 34 preferably operates in a fluid which is made tocirculate through a cooling device (not shown) by means of a pipe 72.

In FIG. 2, a self-adjustment member 52′ is shown, which adjusts theinitial position of the hydraulic piston 46′ as the friction discs 36wear. Apart from the features described above in connection with FIG. 2,the construction of other components of the planetary transmissionaccording to FIG. 2 essentially corresponds to the connection of thecomponents described in connection with the planetary transmissionaccording to FIG. 1.

1. Planetary transmission apparatus for use in a vehicle, comprising aplanet carrier (2), on which at least one planet wheel (4) is mounted, avehicle-wheel hub (16) connected to the planet carrier (2), a statichousing (28) which is adapted to be connected to the vehicle and inwhich the hub (16) is mounted, and a friction brake (34) arranged on anouter periphery of the planet carrier (2) and acting directly betweenthe planet carrier (2) and the static housing (28), wherein the hub (16)and the planet carrier (2) are interconnected by means of a firstsplined connection (14, 21).
 2. Planetary transmission apparatusaccording to claim 1, characterized in that the planet carrier (2)comprises a splined hole (12), the centre line (15) of which coincideswith the axis of rotation of the planet carrier (2) and in that the hub(16) comprises a splined journal (20) which is arranged in the hole (12)of the planet carrier (2).
 3. Planetary transmission apparatus accordingto claim 2, characterized in that the splined journal (20) of the hub(16) is axially fixed in the splined hole (12) of the planet carrier (2)by means of a plate (19) arranged at a first end (18) of the hub (16).4. Planetary transmission apparatus according to claim 1, characterizedin that the friction brake (34) comprises a set of first friction discs(36) arranged on the periphery of the planet carrier (2) and a set ofsecond friction discs (40) arranged on an inner side of the statichousing (28).
 5. Planetary transmission apparatus according to claim 4,characterized in that the first and second friction discs (36 and 40respectively) are axially displaceable on the planet carrier (29) andthe static housing (28) respectively.
 6. Planetary transmissionapparatus according to claim 5, characterized in that a first pressureplate (32, 32′) for the friction brake (34) is arranged on the statichousing (28) and in that a second pressure plate (44) is arranged so asto be displaced, on braking, in the direction of the first pressureplate (32) so as to compress the first and second friction discs (36 and40 respectively) between the first and second pressure plates (32, 44).7. Planetary transmission apparatus according to claim 6, characterizedin that at least one hydraulic piston (46, 46) is arranged in the statichousing (28) and is arranged so as to displace, on braking, the secondpressure plate (44) in the direction of the first pressure plate (32).8. Planetary transmission apparatus according to claim 7, characterizedin that an annular duct (48) is arranged in the static housing (28) andis intended to contain hydraulic fluid and in that the annular duct (48)has a fluid connection to the at least one hydraulic cylinder (46, 46′).9. Planetary transmission apparatus according to claim 7, characterizedin that the at least one hydraulic cylinder (46 46′) comprises aself-adjustment member (52) which, via a sleeve (53), is arrangeddisplaceably in a hole (54) in the housing (28), a pin (56) movableaxially in the sleeve (53) being connected to the hydraulic piston (46,46′).
 10. Planetary transmission apparatus according to claim 1,characterized in that an outer gear ring (30, 30′) is arranged on thestatic housing (28) and in that an inner sun wheel (10) is arranged on adrive shaft (6) of the vehicle.
 11. Planetary transmission apparatusaccording to claim 6, characterized in that an outer gear ring (30, 30′)is arranged on the first pressure plate (32, 32′).
 12. Planetarytransmission apparatus according to claim 10, characterized in that theouter gear ring (30′) is connected to the static housing (28) by meansof a second splined connection (42, 74).
 13. Planetary transmissionapparatus according to claim 1, characterized in that a sensor (68)arranged in the housing (18) is adapted to interact with a surface onthe periphery of the planet carrier (2) so as in this way to sense thespeed of rotation of the planet carrier (2).
 14. Planetary transmissionapparatus for use in a vehicle, comprising a planet carrier (2), onwhich at least one planet wheel (4) is mounted, a vehicle-wheel hub (16)connected to the planet carrier (2), a static housing (28) which isadapted to be connected to the vehicle and in which the hub (16) ismounted, and a friction brake (34) arranged on an outer periphery of theplanet carrier (2) and acting directly between the planet carrier (2)and the static housing (28), wherein an outer gear ring (30′) isarranged so as to interact with the at least one planet wheel (4) and inthat the outer gear ring (30′) is connected to the static housing (28)by means of a second splined connection (42, 74).
 15. Planetarytransmission apparatus according to claim 14, characterized in thatsplines (74) on an outer periphery of the outer gear ring (30′) and inthat splines (42) are arranged in the housing (28), which splines (42,74) form the second splined connection (42, 74).
 16. Planetarytransmission apparatus according to claim 14, characterized in that thefriction brake (34) comprises a set of first friction discs (36)arranged on the periphery of the planet carrier (2) and a set of secondfriction discs (40) arranged on an inner side of the static housing(28), which second friction discs (40) are arranged so as to engage withthe splines (42) in the housing (28).
 17. Planetary transmissionapparatus according to claim 16, characterized in that the outer gearring (30′) forms a first pressure plate (32′) which is arranged so as tocompress, on braking, the first and second friction discs (36, 40). 18.Planetary transmission apparatus for use in a vehicle, comprising: aplanet carrier ( 2 ), on which at least one planet wheel ( 4 ) ismounted, a vehicle-wheel hub ( 16 ) connected to the planet carrier ( 2), a static housing ( 28 ) which is adapted to be connected to thevehicle and in which the hub ( 16 ) is mounted, and a hydraulicallyactivated friction brake ( 34 ) arranged on an outer periphery of theplanet carrier ( 2 ) and acting directly between the planet carrier ( 2) and the static housing ( 28 ), and wherein the hub ( 16 ) and theplanet carrier ( 2 ) are interconnected by means of a first splinedconnection ( 14, 21 ) and the planet carrier ( 2 ) being of one-piececonstruction and wherein the planet carrier ( 2 ) extends solidly in aradial direction between a centered hole ( 12 ) thereof and the outerperiphery of the planet carrier ( 2 ) upon which the multi-disc brake (34 ) is arranged.
 19. The planetary transmission according to claim 18,wherein the centered hole ( 12 ) of the planet carrier ( 2 ) is alongitudinal through-hole.
 20. The planetary transmission according toclaim 19, wherein splines ( 14 ) are provided at an interior surface ofthe longitudinal through-hole ( 12 ).
 21. The planetary transmissionapparatus according to claim 18, wherein the centered hole ( 12 ) formsa portion of the first splined connection ( 14, 21 ).
 22. A planetarytransmission apparatus for use in a vehicle, comprising: a planetcarrier ( 2 ), on which at least one planet wheel ( 4 ) is mounted, avehicle-wheel hub ( 16 ) connected to the planet carrier ( 2 ), a statichousing ( 28 ) which is adapted to be connected to the vehicle and inwhich the hub ( 16 ) is mounted; a friction brake ( 34 ) arranged on anouter periphery of the planet carrier ( 2 ) and acting directly betweenthe planet carrier ( 2 ) and the static housing ( 28 ); the hub ( 16 )and the planet carrier ( 2 ) are interconnected by means of a firstsplined connection ( 14, 21 ) and the hub ( 16 ) being of one-piececonstruction with a splined journal ( 20 ) that forms a portion of thefirst splined connection ( 14, 21 ) and wherein the planet carrier ( 2 )extends solidly in a radial direction between a centered hole ( 12 )thereof and the outer periphery of the planet carrier ( 2 ) upon whichthe multi-disc brake ( 34 ) is arranged, wherein the centered hole ( 12) of the planet carrier ( 2 ) is a longitudinal through-hole, andwherein splines ( 14 ) are provided at an interior surface of thelongitudinal through-hole ( 12 ).
 23. The planetary transmissionapparatus according to any one of claims 18 and 22, wherein the frictionbrake ( 34 ) comprises a set of first friction discs ( 36 ) arranged onthe periphery of the planet carrier ( 2 ) and a set of second frictiondiscs ( 40 ) arranged on an inner side of the static housing ( 28 ). 24.The planetary transmission apparatus according to claim 23, wherein thefirst and second friction discs ( 36 and 40 respectively) are axiallydisplaceable on the planet carrier ( 29 ) and the static housing ( 28 )respectively.
 25. The planetary transmission apparatus according toclaim 24, wherein a first pressure plate ( 32, 32′) for the frictionbrake ( 34 ) is arranged on the static housing ( 28 ) and in that asecond pressure plate ( 44 ) is arranged so as to be displaced, onbraking, in the direction of the first pressure plate ( 32 ) so as tocompress the first and second friction discs ( 36 and 40 respectively)between the first and second pressure plates ( 32, 44 ).
 26. Theplanetary transmission apparatus according to claim 25, wherein an outergear ring ( 30, 30′) is arranged on the first pressure plate ( 32, 32′).27. The planetary transmission apparatus according to claim 25, whereinat least one hydraulic piston ( 46, 46′) is arranged in the statichousing ( 28 ) and is arranged so as to displace, on braking, the secondpressure plate ( 44 ) in the direction of the first pressure plate ( 32).
 28. The planetary transmission apparatus according to claim 27,wherein an annular duct ( 48 ) is arranged in the static housing ( 28 )and is intended to contain hydraulic fluid and in that the annular duct( 48 ) has a fluid connection to the at least one hydraulic piston ( 46,46′).
 29. The planetary transmission apparatus according to claim 27,wherein the at least one hydraulic piston ( 46, 46′) comprises aself-adjustment member ( 52 ) which, via a sleeve ( 53 ), is arrangeddisplaceably in a hole ( 54 ) in the housing ( 28 ), a pin ( 56 )movable axially in the sleeve ( 53 ) being connected to the hydraulicpiston ( 46, 46′).
 30. The planetary transmission apparatus according toany one of claims 18 and 22, further comprising an outer gear ring ( 30,30′) arranged on the static housing ( 28 ) and an inner sun wheel ( 10 )arranged on a drive shaft ( 6 ) of the vehicle.
 31. The planetarytransmission apparatus according to claim 29, wherein the outer gearring ( 30, 30′) is connected to the static housing ( 28 ) by means of asecond splined connection ( 42, 74 ).
 32. The planetary transmissionapparatus according to any one of claims 18 and 22, further comprising asensor ( 68 ) arranged in the housing ( 28 ) that is adapted to interactwith a surface on the periphery of the planet carrier ( 2 ) so as inthis way to sense the speed of rotation of the planet carrier ( 2 ). 33.The planetary transmission apparatus according to any one of claims 18and 22, further comprising an outer gear ring ( 30′) arranged so as tointeract with the at least one planet wheel ( 4 ) and in that the outergear ring ( 30′) is connected to the static housing ( 28 ) by means of asecond splined connection ( 42, 74 ).
 34. The planetary transmissionapparatus according to claim 33, further comprising splines ( 74 ) on anouter periphery of the outer gear ring ( 30′) and splines ( 42 )arranged in the housing ( 28 ), said splines ( 42, 74 ) forming thesecond splined connection ( 42, 74 ).
 35. The planetary transmissionapparatus according to claim 33, wherein the friction brake ( 34 )comprises a set of first friction discs ( 36 ) arranged on the peripheryof the planet carrier ( 2 ) and a set of second friction discs ( 40 )arranged on an inner side of the static housing ( 28 ), which secondfriction discs ( 40 ) are arranged so as to engage with the splines ( 42) in the housing ( 28 ).
 36. The planetary transmission apparatusaccording to claim 33, wherein the outer gear ring ( 30′) forms a firstpressure plate ( 32′) which is arranged so as to compress, on braking,the first and second friction discs ( 36, 40 ).
 37. The planetarytransmission apparatus according to any one of claims 18 and 22, furthercomprising a plurality of individual pistons that actuate the frictionbrake ( 34 ) and which are distributed concentrically about the planetcarrier within the static housing ( 28 ).
 38. The planetary transmissionapparatus according to any one of claims 18 and 22, wherein saidfriction brake ( 34 ) consists of a fluid-cooled multi-disc frictionbrake configured to brake the planet carrier and which has a first setof brake discs mounted on the outer periphery of the planet carrier forrotation therewith and a second set of brake discs mounted to the statichousing ( 28 ).
 39. The planetary transmission apparatus according toclaim 38, further comprising a concentrically oriented disc plateconfigured to actuate the fluid-cooled multi-disc brake responsively toapplied hydraulic pressure.
 40. The planetary transmission according toclaim 39, further comprising a plurality of concentrically distributedhydraulic pistons configured to actuate the disc plate therebycompressing the brake discs sets together for braking the planetcarrier.
 41. The planetary transmission according to claim 40, furthercomprising an annular duct in fluid communication with each of theplurality of concentrically distributed hydraulic pistons which isarranged to commonly supply actuating hydraulic fluid to each of thehydraulic pistons.
 42. The planetary transmission according to claim 38,further comprising a helical spring operatively arranged with thefluid-cooled multi-disc brake and configured to return the brake to aninitial position after braking.
 43. The planetary transmission accordingto claim 38, further comprising a plurality of concentricallydistributed helical springs operatively arranged with the fluid-cooledmulti-disc brake and configured to return the brake to an initialposition after braking.
 44. The planetary transmission according toclaim 38, further comprising a self-adjustment member operativelyarranged with the fluid-cooled multi-disc brake and configured to adjustinitial braking positions of the brake responsive to friction-wear ofthe brake discs.
 45. The planetary transmission according to claim 38,wherein each set of brake discs is axially movable and circumferentiallyfixed on splines.
 46. The planetary transmission according to claim 38,wherein the first set of brake discs is axially movable andcircumferentially fixed on splines peripherally formed on the planetcarrier.
 47. The planetary transmission according to claim 38, whereinthe second set of brake discs is axially movable and circumferentiallyfixed on splines formed at the static transmission housing.
 48. Theplanetary transmission according to claim 38, wherein the outer gearring forms a pressure plate of the brake.
 49. The planetary transmissionaccording to claim 38, wherein the outer gear ring establishes a staticpressure plate against which the sets of brake discs are compressedduring braking of the planet carrier.
 50. The planetary transmissionaccording to claim 38, wherein the outer gear ring is rotationally fixedupon internal splines of the static transmission housing.
 51. Theplanetary transmission according to claim 50, wherein the outer gearring has splines arranged on an outer periphery thereof and which areconfigured for mating engagement with the internal splines of thetransmission housing.
 52. The planetary transmission according to claim38, further comprising a sensor arranged in the transmission housing fordetecting an operational condition of the planetary transmission. 53.The planetary transmission according to claim 38, further comprising asensor arranged in the transmission housing that detects an operationalcondition of the planetary transmission that corresponds to a travelingspeed of a vehicle in which the transmission is included.
 54. Theplanetary transmission according to claim 38, wherein the planet carrierextends solidly in a radial direction between a centered hole thereofand the outer periphery of the planet carrier upon which the multi-discbrake is arranged.
 55. The planetary transmission according to claim 54,wherein the centered hole of the planet carrier is a longitudinalthrough-hole.
 56. The planetary transmission according to claim 55,wherein splines are provided at an interior surface of the longitudinalthrough-hole.
 57. The planetary transmission according to claim 38,wherein the multi-disc brake is a hydraulically activated friction brakeacting directly between the planet carrier and the static transmissionhousing.
 58. The planetary transmission according to claim 38, whereinthe hub is mounted by roller bearings on an inside of the statichousing.
 59. The planetary transmission according to claim 38, whereinthe hub is mounted by two roller bearings arranged at a distance, onefrom the other, in a direction of an axis of rotation of the planetcarrier and an outer portion of each roller bearing is arranged on aninside of the static housing.
 60. The planetary transmission accordingto claim 59, wherein an inner portion of one of the two roller bearingsis arranged on an outside of the hub.
 61. The planetary transmissionaccording to claim 59, wherein an inner portion of each of the tworoller bearings is arranged on an outside of the hub.